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Realm is a mobile database that runs directly inside phones, tablets or wearables. This repository holds the source code for the Java version of Realm, which currently runs only on Android.

Realm Kotlin

The Realm Kotlin SDK is now GA and can be used for both Android and Kotlin Multiplatform. While we are still adding features, please consider using Realm Kotlin for any new project, and let us know if you miss anything there!

Features

Getting Started

Please see the detailed instructions in our docs to add Realm to your project.

Documentation

Documentation for Realm can be found at mongodb.com/docs/atlas/device-sdks/sdk/java/. The API reference is located at mongodb.com/docs/atlas/device-sdks/sdk/java/api/.

Getting Help

Using Snapshots

If you want to test recent bugfixes or features that have not been packaged in an official release yet, you can use a -SNAPSHOT release of the current development version of Realm via Gradle, available on Sonatype OSS

buildscript {
    repositories {
        mavenCentral()
        google()
        maven {
            url 'https://oss.sonatype.org/content/repositories/snapshots/'
        }
        jcenter()
    }
    dependencies {
        classpath "io.realm:realm-gradle-plugin:<version>-SNAPSHOT"
    }
}

allprojects {
    repositories {
        mavenCentral()
        google()
        maven {
            url 'https://oss.sonatype.org/content/repositories/snapshots/'
        }
        jcenter()
    }
}

See version.txt for the latest version number.

Building Realm

In case you don't want to use the precompiled version, you can build Realm yourself from source.

Prerequisites

It would be a good idea to add all of the symbol definitions (and their accompanying launchctl commands, if you are using macOS) to your ~/.profile (or ~/.zprofile if the login shell is zsh)

Download sources

You can download the source code of Realm Java by using git. Since realm-java has git submodules, use --recursive when cloning the repository.

git clone git@github.com:realm/realm-java.git --recursive

or

git clone https://github.com/realm/realm-java.git --recursive

Build

Once you have completed all the pre-requisites building Realm is done with a simple command.

./gradlew assemble

That command will generate:

The full build may take an hour or more, to complete.

Building from source

It is possible to build Realm Java with the submodule version of Realm Core. This is done by providing the following parameter when building: -PbuildCore=true.

./gradlew assembleBase -PbuildCore=true

You can turn off interprocedural optimizations with the following parameter: -PenableLTO=false.

./gradlew assembleBase -PenableLTO=false`

Note: Building the Base variant would always build realm-core.

Note: Interprocedural optimizations are enabled by default.

Note: If you want to build from source inside Android Studio, you need to update the Gradle parameters by going into the Realm projects settings Settings > Build, Execution, Deployment > Compiler > Command-line options and add -PbuildCore=true or -PenableLTO=false to it. Alternatively you can add it into your gradle.properties:

buildCore=true
enableLTO=false

Note: If building on OSX you might like to prevent Gatekeeper to block all NDK executables by disabling it: sudo spctl --master-disable. Remember to enable it afterwards: sudo spctl --master-enable

Other Commands

Generating the Javadoc using the command above may generate warnings. The Javadoc is generated despite the warnings.

Upgrading Gradle Wrappers

All gradle projects in this repository have wrapper task to generate Gradle Wrappers. Those tasks refer to gradle property defined in /dependencies.list to determine Gradle Version of generating wrappers. We have a script ./tools/update_gradle_wrapper.sh to automate these steps. When you update Gradle Wrappers, please obey the following steps.

  1. Edit gradle property in defined in /dependencies.list to new Gradle Wrapper version.
  2. Execute /tools/update_gradle_wrapper.sh.

Gotchas

The repository is organized into six Gradle projects:

This means that ./gradlew clean and ./gradlew cleanExamples will fail if assembleExamples has not been executed first. Note that IntelliJ does not support multiple projects in the same window so each of the six Gradle projects must be imported as a separate IntelliJ project.

Since the repository contains several completely independent Gradle projects, several independent builds are run to assemble it. Seeing a line like: :realm:realm-library:compileBaseDebugAndroidTestSources UP-TO-DATE in the build log does not imply that you can run ./gradlew :realm:realm-library:compileBaseDebugAndroidTestSources.

Examples

The ./examples folder contains many example projects showing how Realm can be used. If this is the first time you checkout or pull a new version of this repository to try the examples, you must call ./gradlew installRealmJava from the top-level directory first. Otherwise, the examples will not compile as they depend on all Realm artifacts being installed in mavenLocal().

Standalone examples can be downloaded from website.

Running Tests on a Device

To run these tests, you must have a device connected to the build computer, and the adb command must be in your PATH

  1. Connect an Android device and verify that the command adb devices shows a connected device:

    adb devices
List of devices attached
004c03eb5615429f device

  2. Run instrumentation tests:

    cd realm
./gradlew connectedBaseDebugAndroidTest

These tests may take as much as half an hour to complete.

Running Tests Using The Realm Object Server

Tests in realm/realm-library/src/syncIntegrationTest require a running testing server to work. A docker image can be built from tools/sync_test_server/Dockerfile to run the test server. tools/sync_test_server/start_server.sh will build the docker image automatically.

To run a testing server locally:

  1. Install docker and run it.

  2. Run tools/sync_test_server/start_server.sh:

    cd tools/sync_test_server
./start_server.sh

    This command will not complete until the server has stopped.

  3. Run instrumentation tests

    In a new terminal window, run:

    cd realm
./gradlew connectedObjectServerDebugAndroidTest

Note that if using VirtualBox (Genymotion), the network needs to be bridged for the tests to work. This is done in VirtualBox > Network. Set "Adapter 2" to "Bridged Adapter".

These tests may take as much as half an hour to complete.

Contributing

See CONTRIBUTING.md for more details!

This project adheres to the MongoDB Code of Conduct. By participating, you are expected to uphold this code. Please report unacceptable behavior to community-conduct@mongodb.com.

The directory realm/config/studio contains lint and style files recommended for project code. Import them from Android Studio with Android Studio > Preferences... > Code Style > Manage... > Import, or Android Studio > Preferences... > Inspections > Manage... > Import. Once imported select the style/lint in the drop-down to the left of the Manage... button.

License

Realm Java is published under the Apache 2.0 license.

Realm Core is also published under the Apache 2.0 license and is available here.

Feedback

If you use Realm and are happy with it, all we ask is that you, please consider sending out a tweet mentioning @realm to share your thoughts!

And if you don't like it, please let us know what you would like improved, so we can fix it!

<img style="width: 0px; height: 0px;" src="https://3eaz4mshcd.execute-api.us-east-1.amazonaws.com/prod?s=https://github.com/realm/realm-java#README.md">